CN114451012A - Carrier Aggregation (CA) configuration during Dual Activity Protocol Stack (DAPs) Handover (HO) - Google Patents

Abstract

Certain aspects of the present disclosure relate to a method for wireless communication. In summary, the method comprises: receiving a message for a Dual Activity Protocol Stack (DAPs) Handover (HO) from a source network entity to a target network entity, wherein Carrier Aggregation (CA) with the source network entity is configured prior to receiving the message for the HO; deactivating CA in response to receiving a message for Handover (HO) to activate a single carrier mode with a source network entity; and performing a HO from the source network entity to the target network entity during a HO period, wherein a single carrier mode is maintained with the source network entity during at least a portion of the HO period, and wherein a connection is maintained with the target network entity during at least the portion of the HO period.

Description

Carrier Aggregation (CA) configuration during Dual Activity Protocol Stack (DAPs) Handover (HO)

Cross Reference to Related Applications

This application claims benefit from U.S. application No.17/061,518 filed on day 10/1 2020, which claims benefit from and priority over U.S. provisional application No.62/911,013 filed on day 10/4 2019, both of which are hereby assigned to the assignee of the present application and are hereby expressly incorporated by reference in their entirety for all applicable purposes as if fully set forth below.

Technical Field

Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for handover management.

Background

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcast, and so on. These wireless communication systems may employ multiple-access techniques capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple-access systems include third generation partnership project (3GPP) Long Term Evolution (LTE) systems, LTE-advanced (LTE-a) systems, Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems, to name a few.

In some examples, a wireless multiple-access communication system may include multiple Base Stations (BSs) that are each capable of simultaneously supporting communication for multiple communication devices, otherwise referred to as User Equipments (UEs). In an LTE or LTE-a network, a set of one or more base stations may define an evolved node b (enb). In other examples (e.g., in a next generation, New Radio (NR), or 5G network), a wireless multiple-access communication system may include a plurality of Distributed Units (DUs) (e.g., Edge Units (EUs), Edge Nodes (ENs), Radio Heads (RHs), intelligent radio heads (SRHs), Transmit Receive Points (TRPs), etc.) in communication with a plurality of Central Units (CUs) (e.g., Central Nodes (CNs), Access Node Controllers (ANCs), etc.), where a set of one or more DUs in communication with a CU may define an access node (e.g., which may be referred to as a BS, 5G NB, next generation node B (gNB or gnnodeb), Transmit Receive Point (TRP), etc.). A BS or DU may communicate with a set of UEs on a downlink channel (e.g., for transmissions from the BS or DU to the UEs) and an uplink channel (e.g., for transmissions from the UEs to the BS or DU).

These multiple access techniques have been employed in various telecommunications standards to provide a common protocol that enables different wireless devices to communicate at the urban level, national level, regional level, or even global level. NR (e.g., new radio or 5G) is an example of an emerging telecommunications standard. NR is a set of enhancements to the LTE mobile standard promulgated by 3 GPP. NR is designed to better support mobile broadband internet access by improving spectral efficiency, reducing costs, improving services, utilizing new spectrum, and using OFDMA with Cyclic Prefix (CP) on the Downlink (DL) and on the Uplink (UL) to better integrate with other open standards. For these purposes, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

However, as the demand for mobile broadband access continues to grow, there is a need for further improvements in NR and LTE technologies. Preferably, these improvements should be applicable to other multiple access technologies and telecommunications standards that employ these technologies.

Disclosure of Invention

The systems, methods, and devices of the present disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the present disclosure as expressed by the claims which follow, some features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled "detailed description" one will understand how the features of this disclosure provide advantages that include improved communication between access points and stations in a wireless network.

Certain aspects of the present disclosure relate to a method for wireless communication. In summary, the method comprises: receiving a message for a Dual Activity Protocol Stack (DAPs) Handover (HO) from a source network entity to a target network entity, wherein a CA with the source network entity is configured prior to receiving the message for the HO; deactivating the CA in response to receiving the message for HO to activate a single carrier mode with the source network entity; and performing the HO from the source network entity to the target network entity during a HO period, wherein the single carrier mode is maintained with the source network entity during at least a portion of the HO period, and wherein a connection is maintained with the target network entity during the at least a portion of the HO period.

Certain aspects of the present disclosure relate to a method for wireless communication. In summary, the method comprises: receiving a message for a dual-DAPs HO from a source network entity to a target network entity, wherein a CA is configured for communication with the source network entity prior to receiving the message for the HO; activating a dormant CA mode with the source network entity in response to the receiving the message for HO; and performing the HO from the source network entity to the target network entity during a HO period, wherein the dormant CA mode is maintained with the source network entity during at least a portion of the HO period, and wherein a connection is maintained with the target network entity during the at least a portion of the HO period.

Certain aspects of the present disclosure relate to a method for wireless communication. In summary, the method comprises: receiving a message for a dual DAPs HO from a source network entity to a target network entity, wherein a CA is configured for communication with the source network entity prior to receiving the message; and performing the HO from the source network entity to the target network entity during a HO period, wherein the CA mode with the source network entity is maintained during at least a portion of the HO period, and wherein a connection with the target network entity is maintained during the at least a portion of the HO period.

Certain aspects of the present disclosure relate to a method for wireless communication. In summary, the method comprises: generating a message for a dual-DAPs HO of a UE from a source network entity to a target network entity, wherein CA is configured for communication between the UE and the source network entity prior to sending the message for HO, and wherein the message indicates to the UE to activate a single carrier mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and sending the message for the HO to the UE.

Certain aspects of the present disclosure relate to a method for wireless communication. In summary, the method comprises: generating a message for a dual-DAPs HO of a UE from a source network entity to a target network entity, wherein CA is configured for communication between the UE and the source network entity prior to sending the message for the HO, wherein the message indicates to the UE to activate a dormant CA mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and sending the message to the UE.

Certain aspects of the present disclosure relate to a method for wireless communication. In summary, the method comprises: generating a message for a dual-DAPs HO of a UE from a source network entity to a target network entity, wherein a CA mode is configured for communication between the UE and the source network entity prior to sending the message for HO, and wherein the message instructs the UE to maintain the CA mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and sending the message for HO to the UE.

Certain aspects of the present disclosure relate to an apparatus for wireless communication. In summary, the apparatus includes a memory and one or more processors coupled to the memory, the memory and the one or more processors configured to: receiving a message for a DAPs HO from a source network entity to a target network entity, wherein a CA with the source network entity is configured prior to receiving the message for HO; deactivating the CA in response to receiving the message for HO to activate a single carrier mode with the source network entity; and performing the HO from the source network entity to the target network entity during a HO period, wherein the single carrier mode is maintained with the source network entity during at least a portion of the HO period, and wherein a connection is maintained with the target network entity during the at least a portion of the HO period.

Certain aspects of the present disclosure relate to an apparatus for wireless communication. In summary, the apparatus includes a memory and one or more processors coupled to the memory, the memory and the one or more processors configured to: receiving a message for a dual-DAPs HO from a source network entity to a target network entity, wherein a CA is configured for communication with the source network entity prior to receiving the message for the HO; activating a dormant CA mode with the source network entity in response to the receiving the message for HO; and performing the HO from the source network entity to the target network entity during a HO period, wherein the dormant CA mode is maintained with the source network entity during at least a portion of the HO period, and wherein a connection is maintained with the target network entity during the at least a portion of the HO period.

Certain aspects of the present disclosure relate to an apparatus for wireless communication. In summary, the apparatus includes a memory and one or more processors coupled to the memory, the memory and the one or more processors configured to: receiving a message for a dual DAPs HO from a source network entity to a target network entity, wherein a CA is configured for communication with the source network entity prior to receiving the message; and performing the HO from the source network entity to the target network entity during a HO period, wherein the CA mode with the source network entity is maintained during at least a portion of the HO period, and wherein a connection with the target network entity is maintained during the at least a portion of the HO period.

Certain aspects of the present disclosure relate to an apparatus for wireless communication. In general, the apparatus includes a memory and one or more processors coupled to the memory, the memory and the one or more processors configured to: generating a message for a dual-DAPs HO of a UE from a source network entity to a target network entity, wherein CA is configured for communication between the UE and the source network entity prior to sending the message for HO, and wherein the message indicates to the UE to activate a single carrier mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and sending the message for the HO to the UE.

Certain aspects of the present disclosure relate to an apparatus for wireless communication. In summary, the apparatus includes a memory and one or more processors coupled to the memory, the memory and the one or more processors configured to: generating a message for a dual-DAPs HO of a UE from a source network entity to a target network entity, wherein CA is configured for communication between the UE and the source network entity prior to sending the message for the HO, wherein the message indicates to the UE to activate a dormant CA mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and sending the message to the UE.

Certain aspects of the present disclosure relate to an apparatus for wireless communication. In summary, the apparatus includes a memory and one or more processors coupled to the memory, the memory and the one or more processors configured to: generating a message for a dual-DAPs HO of a UE from a source network entity to a target network entity, wherein a CA mode is configured for communication between the UE and the source network entity prior to sending the message for HO, and wherein the message instructs the UE to maintain the CA mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and sending the message for HO to the UE.

Certain aspects of the present disclosure relate to an apparatus for wireless communication. In summary, the apparatus comprises: means for receiving a message for a DAPs HO from a source network entity to a target network entity, wherein a CA with the source network entity is configured prior to receiving the message for HO; means for deactivating the CA to activate a single carrier mode with the source network entity in response to receiving the message for HO; and means for performing the HO from the source network entity to the target network entity during a HO period, wherein the single carrier mode is maintained with the source network entity during at least a portion of the HO period, and wherein a connection is maintained with the target network entity during the at least a portion of the HO period.

Certain aspects of the present disclosure relate to an apparatus for wireless communication. In summary, the apparatus comprises: means for receiving a message for a dual-DAPs HO from a source network entity to a target network entity, wherein a CA is configured for communication with the source network entity prior to receiving the message for the HO; means for activating a dormant CA mode with the source network entity in response to the receiving the message for HO; and means for performing the HO from the source network entity to the target network entity during a HO period, wherein the dormant CA mode is maintained with the source network entity during at least a portion of the HO period, and wherein a connection is maintained with the target network entity during the at least a portion of the HO period.

Certain aspects of the present disclosure relate to an apparatus for wireless communication. In summary, the apparatus comprises: means for receiving a message for a dual-DAPs HO from a source network entity to a target network entity, wherein a CA is configured for communication with the source network entity prior to receiving the message; and means for performing the HO from the source network entity to the target network entity during a HO period, wherein the CA mode with the source network entity is maintained during at least a portion of the HO period, and wherein a connection with the target network entity is maintained during the at least a portion of the HO period.

Certain aspects of the present disclosure relate to an apparatus for wireless communication. In summary, the apparatus comprises: means for generating a message for a dual-DAPs HO of a UE from a source network entity to a target network entity, wherein CA is configured for communication between the UE and the source network entity prior to sending the message for HO, and wherein the message indicates to the UE to activate a single carrier mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and means for sending the message for the HO to the UE.

Certain aspects of the present disclosure relate to an apparatus for wireless communication. In summary, the apparatus comprises: means for generating a message for a dual-DAPs HO of a UE from a source network entity to a target network entity, wherein CA is configured for communication between the UE and the source network entity prior to sending the message for the HO, wherein the message indicates to the UE to activate a dormant CA mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and means for transmitting the message to the UE.

Certain aspects of the present disclosure relate to an apparatus for wireless communication. In summary, the apparatus comprises: means for generating a message for a dual-DAPs HO of a UE from a source network entity to a target network entity, wherein a CA mode is configured for communication between the UE and the source network entity prior to sending the message for the HO, and wherein the message instructs the UE to maintain the CA mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and means for sending the message for HO to the UE.

Certain aspects of the present disclosure relate to a computer-readable medium having instructions stored thereon that cause a processor to: receiving a message for a DAPs HO from a source network entity to a target network entity, wherein a CA with the source network entity is configured prior to receiving the message for HO; deactivating the CA in response to receiving the message for HO to activate a single carrier mode with the source network entity; and performing the HO from the source network entity to the target network entity during a HO period, wherein the single carrier mode is maintained with the source network entity during at least a portion of the HO period, and wherein a connection is maintained with the target network entity during the at least a portion of the HO period.

Certain aspects of the present disclosure relate to a computer-readable medium having instructions stored thereon that cause a processor to: receiving a message for a dual-DAPs HO from a source network entity to a target network entity, wherein a CA is configured for communication with the source network entity prior to receiving the message for the HO; activating a dormant CA mode with the source network entity in response to the receiving the message for HO; and performing the HO from the source network entity to the target network entity during a HO period, wherein the dormant CA mode is maintained with the source network entity during at least a portion of the HO period, and wherein a connection is maintained with the target network entity during the at least a portion of the HO period.

Certain aspects of the present disclosure relate to a computer-readable medium having instructions stored thereon that cause a processor to: receiving a message for a dual DAPs HO from a source network entity to a target network entity, wherein a CA is configured for communication with the source network entity prior to receiving the message; and performing the HO from the source network entity to the target network entity during a HO period, wherein the CA mode with the source network entity is maintained during at least a portion of the HO period, and wherein a connection with the target network entity is maintained during the at least a portion of the HO period.

Certain aspects of the present disclosure relate to a computer-readable medium having instructions stored thereon that cause a processor to: generating a message for a dual-DAPs HO of a UE from a source network entity to a target network entity, wherein CA is configured for communication between the UE and the source network entity prior to sending the message for HO, and wherein the message indicates to the UE to activate a single carrier mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and sending the message for the HO to the UE.

Certain aspects of the present disclosure relate to a computer-readable medium having instructions stored thereon that cause a processor to: generating a message for a dual-DAPs HO of a UE from a source network entity to a target network entity, wherein CA is configured for communication between the UE and the source network entity prior to sending the message for the HO, wherein the message indicates to the UE to activate a dormant CA mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and sending the message to the UE.

Certain aspects of the present disclosure relate to a computer-readable medium having instructions stored thereon that cause a processor to: generating a message for a dual-DAPs HO of a UE from a source network entity to a target network entity, wherein a CA mode is configured for communication between the UE and the source network entity prior to sending the message for HO, and wherein the message instructs the UE to maintain the CA mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and sending the message for HO to the UE

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed.

Drawings

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description (briefly summarized above) may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects.

Fig. 1 is a block diagram conceptually illustrating an example telecommunications system in accordance with certain aspects of the present disclosure.

Fig. 2 is a block diagram illustrating an example architecture of a distributed Radio Access Network (RAN) in accordance with certain aspects of the present disclosure.

Fig. 3 is a block diagram illustrating an example of a communication protocol stack for implementing in an example RAN architecture, in accordance with certain aspects of the present disclosure.

Fig. 4 is a block diagram conceptually illustrating a design of an example Base Station (BS) and User Equipment (UE), in accordance with certain aspects of the present disclosure.

Fig. 5 illustrates an example system architecture for interworking between a 5G system (5GS) and an evolved universal mobile telecommunications system network (E-UTRAN) system in accordance with certain aspects of the present disclosure.

Fig. 6 illustrates an example of a frame format for a telecommunications system in accordance with certain aspects of the present disclosure.

Fig. 7 is a call flow for a Make Before Break (MBB) Handover (HO) in accordance with certain aspects of the present disclosure.

Fig. 8 is a flowchart illustrating example operations for wireless communications by a UE in accordance with certain aspects of the present disclosure.

Fig. 9 is a flow chart illustrating example operations for wireless communications by a BS in accordance with certain aspects of the present disclosure.

Fig. 10 is a timing diagram illustrating a connection pattern of a source cell and a target cell during MBB HO in accordance with certain aspects of the present disclosure.

Fig. 11 is a flowchart illustrating example operations for wireless communications by a UE in accordance with certain aspects of the present disclosure.

Fig. 12 is a flow chart illustrating example operations for wireless communications by a BS according to certain aspects of the present disclosure.

Fig. 13 is a timing diagram illustrating connection patterns of a source cell and a target cell during MBB HO in accordance with certain aspects of the present disclosure.

Fig. 14 is a flowchart illustrating example operations for wireless communications by a UE in accordance with certain aspects of the present disclosure.

Fig. 15 is a flowchart illustrating example operations for wireless communications by a BS in accordance with certain aspects of the present disclosure.

Fig. 16 is a timing diagram illustrating a connection pattern of a source cell and a target cell during MBB HO in accordance with certain aspects of the present disclosure.

Fig. 17 illustrates a communication device that may include various components configured to perform operations for the techniques disclosed herein.

Fig. 18 illustrates a communication device that may include various components configured to perform operations for the techniques disclosed herein.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation.

Detailed Description

The following description provides examples, but does not limit the scope, applicability, or examples set forth in the claims. Changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For example, the described methods may be performed in an order different than described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined into some other examples. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. Moreover, the scope of the present disclosure is intended to cover such an apparatus or method implemented with other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects.

The techniques described herein may be used for various wireless communication technologies such as LTE, CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRA includes wideband CDMA (wcdma) and other variants of CDMA. cdma2000 covers IS-2000, IS-95 and IS-856 standards. TDMA networks may implement radio technologies such as global system for mobile communications (GSM). An OFDMA network may implement radio technologies such as NR (e.g., 5G RA), evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16(WiMAX), IEEE802.20, flash-OFDMA, and the like. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS).

New Radios (NR) are emerging wireless communication technologies under development in conjunction with the 5G technology forum (5 GTF). 3GPP Long Term Evolution (LTE) and LTE-advanced (LTE-A) are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE-A, and GSM are described in documents from an organization entitled "third Generation partnership project" (3 GPP). Cdma2000 and UMB are described in documents from an organization named "third generation partnership project 2" (3GPP 2). The techniques described herein may be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For clarity, although aspects may be described herein using terms commonly associated with 3G and/or 4G wireless technologies, aspects of the present disclosure may be applied in other generation-based communication systems, e.g., 5G and beyond technologies, including NR technologies.

New Radio (NR) access (e.g., 5G technology) may support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidths (e.g., 80MHz or over 80MHz), millimeter wave (mmW) targeting high carrier frequencies (e.g., 25GHz or over 25GHz), massive Machine Type Communication (MTC) targeting non-backward compatible MTC technologies, MTC (MTC), and/or mission critical targeting ultra-reliable low latency communication (URLLC). These services may include latency and reliability requirements. These services may also have different Transmission Time Intervals (TTIs) to meet corresponding quality of service (QoS) requirements. In addition, these services may coexist in the same subframe.

Example Wireless communication System

Fig. 1 illustrates an example wireless communication network 100 in which aspects of the disclosure may be performed. For example, the wireless communication network 100 may be a New Radio (NR) or 5G network.

As shown in fig. 1, the wireless communication network 100 may include a plurality of Base Stations (BSs) 110 and other network entities. A BS may be a station that communicates with a User Equipment (UE). Each BS 110 may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" can refer to a coverage area of a Node B (NB) and/or an NB subsystem serving the coverage area, depending on the context in which the term is used. In NR systems, the terms "cell" and next generation node B (gNB or gnnodeb), NR BS, 5G NB, Access Point (AP) or Transmission Reception Point (TRP) may be interchangeable. In some examples, the cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of the mobile BS. In some examples, the base stations may be interconnected with each other and/or with one or more other base stations or network nodes (not shown) in the wireless communication network 100 by various types of backhaul interfaces (e.g., interfaces that are directly physical connections, wireless connections, virtual networks, or use any suitable transport networks).

In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular Radio Access Technology (RAT) and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, air interface, etc. Frequencies may also be referred to as carriers, subcarriers, frequency channels, tones, subbands, and so on. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks having different RATs. In some cases, NR or 5G RAT networks may be deployed.

The BS may provide communication coverage for a macrocell, picocell, femtocell, and/or other type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscriptions. A femto cell may cover a relatively small geographic area (e.g., a residence) and may allow restricted access by UEs having an association with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG), UEs for users in the residence, etc.). The BS for the macro cell may be referred to as a macro BS. The BS for the pico cell may be referred to as a pico BS. The BS for the femto cell may be referred to as a femto BS or a home BS. In the example shown in fig. 1, BSs 110a, 110b, and 110c may be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS 110x may be a pico BS for pico cell 102 x. BSs 110y and 110z may be femto BSs for femtocells 102y and 102z, respectively. A BS may support one or more (e.g., three) cells.

The wireless communication network 100 may also include relay stations. A relay station is a station that receives data transmissions and/or other information from an upstream station (e.g., a BS or a UE) and transmits data transmissions and/or other information to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that relays transmissions for other UEs. In the example shown in fig. 1, relay station 110r may communicate with BS 110a and UE 120r to facilitate communication between BS 110a and UE 120 r. The relay station may also be referred to as a relay BS, a relay, etc.

The wireless communication network 100 may be a heterogeneous network including different types of BSs (e.g., macro BSs, pico BSs, femto BSs, repeaters, etc.). These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference in the wireless communication network 100. For example, macro BSs may have a high transmit power level (e.g., 20 watts), while pico BSs, femto BSs, and repeaters may have a lower transmit power level (e.g., 1 watt).

The wireless communication network 100 may support synchronous operation or asynchronous operation. For synchronous operation, BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, the BSs may have different frame timings, and transmissions from different BSs may not be aligned in time. The techniques described herein may be used for both synchronous and asynchronous operations.

Network controller 130 may couple to a set of BSs and provide coordination and control for these BSs. Network controller 130 may communicate with BS 110 via a backhaul. BSs 110 may also communicate with each other via a wireless or wired backhaul (e.g., directly or indirectly).

UEs 120 (e.g., 120x, 120y, etc.) may be dispersed throughout the wireless communication network 100, and each UE may be stationary or mobile. A UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, a Customer Premises Equipment (CPE), a cellular telephone, a smartphone, a Personal Digital Assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop, a cordless telephone, a Wireless Local Loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, an appliance, a medical device or medical equipment, a biometric sensor/device, a wearable device (e.g., a smartwatch, a smart garment, smart glasses, a smart wristband, smart jewelry (e.g., a smart ring, a smart bracelet, etc.)), an entertainment device (e.g., a music device, a video device, a satellite radio, etc.), a vehicle component or sensor, a smart meter/sensor, an industrial manufacturing device, a smart phone, a Wireless Local Loop (WLL) station, a tablet computer, a camera, a game device, a netbook, a smart book, an ultrabook, an appliance, a medical device, or a smart phone, a smart watch, smart phone, a smart garment, smart watch, smart glasses, a smart wristband, a smart watch, a smart phone, a, A global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium. Some UEs may be considered Machine Type Communication (MTC) devices or evolved MTC (emtc) devices. MTC and eMTC UEs include, for example, a robot, a drone, a remote device, a sensor, a meter, a monitor, a location tag, etc., which may communicate with a BS, another device (e.g., a remote device), or some other entity. The wireless node may provide connectivity, for example, to or from a network (e.g., a wide area network such as the internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered internet of things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.

Some wireless networks (e.g., LTE) utilize Orthogonal Frequency Division Multiplexing (OFDM) on the downlink and single carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, bins, and so on. Each subcarrier may be modulated with data. Typically, modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may depend on the system bandwidth. For example, the spacing of the subcarriers may be 15kHz and the minimum resource allocation, referred to as Resource Blocks (RBs), may be 12 subcarriers (or 180 kHz). Thus, for a system bandwidth of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), the nominal Fast Fourier Transform (FFT) size may be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth may also be divided into subbands. For example, a sub-band may cover 1.8MHz (i.e., 6 resource blocks), and there may be 1, 2, 4, 8, or 16 sub-bands for a system bandwidth of 1.25, 2.5, 5, 10, or 20MHz, respectively.

Although aspects of the examples described herein may be associated with LTE technology, aspects of the disclosure may be applied with other wireless communication systems (e.g., NRs). NR may utilize OFDM with CP on the uplink and downlink, and may include support for half-duplex operation using TDD. Beamforming may be supported and beam directions may be dynamically configured. MIMO transmission with precoding may also be supported. MIMO configuration in DL may support up to 8 transmit antennas with multi-layer DL transmitting up to 8 streams and up to 2 streams per UE. Multi-layer transmission with up to 2 streams per UE may be supported. Aggregation of multiple cells with up to 8 serving cells may be supported.

In some examples, access to the air interface may be scheduled. A scheduling entity (e.g., a BS) allocates resources for communication among some or all of the devices and apparatuses within its service area or cell. The scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communications, the subordinate entity utilizes the resources allocated by the scheduling entity. The base station is not the only entity that can be used as a scheduling entity. In some examples, a UE may serve as a scheduling entity and may schedule resources for one or more subordinate entities (e.g., one or more other UEs), and the other UEs may utilize the resources scheduled by the UE for wireless communications. In some examples, the UE may serve as a scheduling entity in a peer-to-peer (P2P) network and/or in a mesh network. In the mesh network example, in addition to communicating with the scheduling entity, the UEs may also communicate directly with each other.

In fig. 1, a solid line with double arrows indicates desired transmissions between a UE and a serving BS, which is a BS designated to serve the UE on the downlink and/or uplink. The thin dashed line with double arrows indicates interfering transmissions between the UE and the BS.

Fig. 2 illustrates an example architecture of a distributed Radio Access Network (RAN)200 that may be implemented in the wireless communication network 100 shown in fig. 1. As shown in fig. 2, the distributed RAN includes a Core Network (CN)202 and an access node 208.

CN 202 may host core network functions. CN 202 may be centrally deployed. CN 202 functionality may be offloaded (e.g., to Advanced Wireless Services (AWS)) in order to handle peak capacity. CN 202 may include an access and mobility management function (AMF)204 and a User Plane Function (UPF) 206. The AMF 204 and the UPF 206 may perform one or more of the core network functions.

The AN 208 may communicate with the CN 202 (e.g., via a backhaul interface). The AN 208 may communicate with the AMF 204 via AN N2 (e.g., NG-C) interface. The AN 208 may communicate with the UPF 208 via AN N3 (e.g., NG-U) interface. The AN 208 may include a central unit control plane (CU-CP)210, one or more central unit user planes (CU-UP)212, one or more Distributed Units (DU)214 and 218, and one or more antenna/remote radio units (AU/RRUs) 220 and 224. The CU and DU may also be referred to as gNB-CU and gNB-DU, respectively. One or more components of AN 208 may be implemented in the gNB 226. AN 208 may communicate with one or more neighboring gnbs.

The CU-CP 210 may be connected to one or more of the DUs 214-218. The CU-CP 210 and DU 214-218 may be connected via the F1-C interface. As shown in FIG. 2, a CU-CP 210 may be connected to multiple DUs, but a DU may be connected to only one CU-CP. Although fig. 2 shows only one CU-UP 212, AN 208 may include multiple CU-UPs. The CU-CP 210 selects the appropriate CU-UP for the requested service (e.g., for the UE).

The CU-UP 212 may be connected to the CU-CP 210. For example, DU-UP 212 and CU-CP 210 may be connected via an E1 interface. The CU-CP 212 may be connected to one or more of the DUs 214-218. CU-UP 212 and DU 214-218 may be connected via the F1-U interface. As shown in fig. 2, a CU-CP 210 may be connected to a plurality of CU-UPs, but a CU-UP may be connected to only one CU-CP.

DUs (e.g., DUs 214, 216, and/or 218) can host one or more TRPs (transmission/reception points, which can include Edge Nodes (ENs), Edge Units (EUs), Radio Heads (RH), intelligent radio heads (SRHs), etc.). The DU may be located at the edge of a Radio Frequency (RF) enabled network. The DU may be connected to multiple CU-UPs that are connected to (e.g., under control of) the same CU-CP (e.g., for RAN sharing, radio as a service (RaaS), and service-specific deployment). The DUs can be configured to provide services to the UEs individually (e.g., dynamic selection) or jointly (e.g., joint transmission). Each DU 214-216 may be connected to one of the AU/RRU 220-224. The DU can be connected to the AU/RRU via each of the F1-C and F1-U interfaces.

The CU-CP 210 may be connected to multiple DUs that are connected to the same CU-UP 212 (e.g., under control of the same CU-UP 212). Connectivity between the CU-UP 212 and the DU may be established through the CU-CP 210. For example, a bearer context management function may be used to establish connectivity between the CU-UP 212 and the DU. Data forwarding between CU-UP 212 may be done via an Xn-U interface.

The distributed RAN200 may support a fronthaul scheme across different deployment types. For example, the RAN200 architecture may be based on the transmitting network capabilities (e.g., bandwidth, delay, and/or jitter). The distributed RAN200 may share features and/or components with LTE. For example, AN 208 may support dual connectivity with NRs and may share a common fronthaul for LTE and NR. The distributed RAN200 may implement cooperation between and among DUs 214 and 218, for example, via CU-CP 212. The inter-DU interface may not be used.

The logical functions may be dynamically distributed among the distributed RANs 200. As will be described in greater detail with reference to fig. 3, a Radio Resource Control (RRC) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, a Physical (PHY) layer, and/or a Radio Frequency (RF) layer may be adaptively placed in the N AN and/or the UE.

Fig. 3 shows a diagram showing an example of a communication protocol stack 300 for implementing in a RAN (e.g., such as RAN 200) according to aspects of the present disclosure. The illustrated communication protocol stack 300 may be implemented by a device operating in a wireless communication system, such as a 5G NR system (e.g., wireless communication network 100). In various examples, the layers of the protocol stack 300 may be implemented as separate software modules, portions of a processor or ASIC, portions of non-co-located devices connected by a communications link, or various combinations thereof. The co-located and non-co-located implementations may be used, for example, in a protocol stack for a network access device or UE. As shown in fig. 3, the system may support various services via one or more protocols. One or more protocol layers of the protocol stack 300 may be implemented by the AN and/or the UE.

As shown in fig. 3, the protocol stack 300 is split in AN (e.g., AN 208 in fig. 2). The RRC layer 305, PDCP layer 310, RLC layer 315, MAC layer 320, PHY layer 325, and RF layer 330 may be implemented by AN. For example, a CU-CP (e.g., CU-CP 210 in FIG. 2) and a CU-UP (e.g., CU-UP 212 in FIG. 2) may implement RRC layer 305 and PDCP layer 310, respectively. The DUs (e.g., DU 214-. AU/RRU (e.g., AU/ RRU 220 and 224 in FIG. 2) may implement PHY layer 325 and RF layer 330. PHY layer 325 may include a high PHY layer and a low PHY layer.

The UE may implement the entire protocol stack 300 (e.g., RRC layer 305, PDCP layer 310, RLC layer 315, MAC layer 320, PHY layer 325, and RF layer 330).

Fig. 4 shows example components of BS 110 and UE 120 (as depicted in fig. 1) that may be used to implement aspects of the present disclosure. For example, antennas 452, processors 466, 458, 464, and/or controller/processor 480 of UE 120, and/or antennas 434, processors 420, 430, 438, and/or controller/processor 440 of BS 110 may be used to perform the various techniques and methods described.

At BS 110, a transmit processor 420 may receive data from a data source 412 and control information from a controller/processor 440. The control information may be used for a Physical Broadcast Channel (PBCH), a Physical Control Format Indicator Channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), a Physical Downlink Control Channel (PDCCH), a group common PDCCH (gc PDCCH), etc. The data may be for a Physical Downlink Shared Channel (PDSCH), etc. Processor 420 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. Processor 420 may also generate reference symbols, e.g., for Primary Synchronization Signals (PSS), Secondary Synchronization Signals (SSS), and cell-specific reference signals (CRS). A Transmit (TX) multiple-input multiple-output (MIMO) processor 430 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to Modulators (MODs) 432a through 432 t. Each modulator 432 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators 432a through 432t may be transmitted via antennas 434a through 434t, respectively.

At UE 120, antennas 452a through 452r may receive the downlink signals from base station 110 and may provide received signals to demodulators (DEMODs) in transceivers 454a through 454r, respectively. Each demodulator 454 may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 456 may obtain received symbols from all demodulators 454a through 454r, perform MIMO detection on the received symbols (if applicable), and provide detected symbols. A receive processor 458 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 120 to a data sink 460, and provide decoded control information to a controller/processor 480.

On the uplink, at UE 120, a transmit processor 464 may receive and process data from a data source 462 (e.g., for a Physical Uplink Shared Channel (PUSCH)) and control information from a controller/processor 480 (e.g., for a Physical Uplink Control Channel (PUCCH)). Transmit processor 464 may also generate reference symbols for a reference signal (e.g., for a Sounding Reference Signal (SRS)). The symbols from transmit processor 464 may be precoded by a TX MIMO processor 466 if applicable, further processed by demodulators (e.g., for SC-FDM, etc.) in transceivers 454a through 454r, and transmitted to base station 110. At BS 110, the uplink signals from UE 120 may be received by antennas 434, processed by modulators 432, detected by a MIMO detector 436 (if applicable), and further processed by a receive processor 438 to obtain decoded data and control information sent by UE 120. A receive processor 438 may provide decoded data to a data sink 439 and decoded control information to a controller/processor 440.

Controllers/ processors 440 and 480 may direct the operation at BS 110 and UE 120, respectively. Processor 440 and/or other processors and modules at BS 110 may perform or direct the performance of processes for the techniques described herein. Memories 442 and 482 may store data and program codes for BS 110 and UE 120, respectively. A scheduler 444 may schedule UEs for data transmission on the downlink and/or uplink.

Fig. 5 illustrates an example system architecture 500 for interworking between a 5GS (e.g., such as distributed RAN 200) and an E-UTRAN-EPC, in accordance with certain aspects of the present disclosure. As shown in fig. 5, the UE 502 may be served by separate RANs 504A and 504B controlled by separate core networks 506A and 506B, with the RAN 504A providing E-UTRA services and the RAN504B providing 5G NR services. The UE may operate under the RAN/CN only or under both at once.

In LTE, the basic Transmission Time Interval (TTI), or packet duration, is a 1ms subframe. In NR, the subframe is still 1ms, but the basic TTI is called a slot. A subframe contains a variable number of slots (e.g., 1, 2, 4, 8, 16.. slots), depending on the subcarrier spacing. NR RB is 12 consecutive frequency subcarriers. NR may support a basic subcarrier spacing of 15KHz and other subcarrier spacings may be defined relative to the basic subcarrier spacing, e.g., 30KHz, 60KHz, 120KHz, 240KHz, etc. The symbol and slot lengths scale with the subcarrier spacing. The CP length also depends on the subcarrier spacing.

Fig. 6 is a diagram showing an example of a frame format 600 for NR. The transmission timeline for each of the downlink and uplink may be divided into units of radio frames. Each radio frame may have a predetermined duration (e.g., 10ms) and may be divided into 10 subframes with indices of 0 through 9, each subframe being 1 ms. Each subframe may include a variable number of slots, depending on the subcarrier spacing. Each slot may include a variable number of symbol periods (e.g., 7 or 14 symbols), depending on the subcarrier spacing. An index may be assigned to a symbol period in each slot. A mini-slot (which may be referred to as a sub-slot structure) refers to a transmission time interval (e.g., 2, 3, or 4 symbols) having a duration less than a slot.

Each symbol in a slot may indicate a link direction (e.g., DL, UL, or flexible) for data transmission, and the link direction for each subframe may be dynamically switched. The link direction may be based on a slot format. Each slot may include DL/UL data as well as DL/UL control information.

In NR, a Synchronization Signal (SS) block is transmitted. The SS block includes PSS, SSs, and two-symbol PBCH. The SS blocks may be transmitted in fixed slot positions (e.g., symbols 0-3 as shown in fig. 6). The PSS and SSS may be used by the UE for cell search and acquisition. The PSS may provide half-frame timing and the SS may provide CP length and frame timing. The PSS and SSS may provide the cell identity. The PBCH carries certain basic system information such as downlink system bandwidth, timing information within the radio frame, SS burst set period, system frame number, etc. The SS blocks may be organized into SS bursts to support beam scanning. Additional system information, such as Remaining Minimum System Information (RMSI), System Information Blocks (SIBs), Other System Information (OSI), may be transmitted on the Physical Downlink Shared Channel (PDSCH) in certain subframes. For mmW, the SS block may be sent up to sixty-four times, e.g., with up to sixty-four different beam directions. The transmission of up to sixty-four SS blocks is referred to as a set of SS bursts. SS blocks in a set of SS bursts are transmitted in the same frequency region, while SS blocks in different sets of SS bursts may be transmitted at different frequency locations.

In some cases, two or more subordinate entities (e.g., UEs) may communicate with each other using sidelink signals. Real-world applications of such sidelink communications may include public safety, proximity services, UE-to-network relays, vehicle-to-vehicle (V2V) communications, internet of everything (IoE) communications, IoT communications, mission critical grids, and/or various other suitable applications. In general, a sidelink signal may refer to a signal transmitted from one subordinate entity (e.g., UE1) to another subordinate entity (e.g., UE2) without the need to relay the communication through a scheduling entity (e.g., UE or BS), even though the scheduling entity may be used for scheduling and/or control purposes. In some examples, the sidelink signals may be transmitted using licensed spectrum (as opposed to wireless local area networks that typically use unlicensed spectrum).

The UE may operate in various radio resource configurations including configurations associated with transmitting pilots using a set of dedicated resources (e.g., Radio Resource Control (RRC) dedicated state, etc.) or configurations associated with transmitting pilots using a set of common resources (e.g., RRC common state, etc.). When operating in the RRC dedicated state, the UE may select a dedicated set of resources for transmitting pilot signals to the network. When operating in the RRC common state, the UE may select a common set of resources for transmitting pilot signals to the network. In either case, the pilot signal transmitted by the UE may be received by one or more network access devices (e.g., AN or DU or portion thereof). Each receiving network access device may be configured to receive and measure pilot signals transmitted on a common set of resources, and also receive and measure pilot signals transmitted on a set of dedicated resources allocated to UEs for which the network access device is a member of the set of network access devices monitoring for the UE. A CU receiving one or more of the network access devices, or receiving measurements to which the network access devices send pilot signals, may use the measurements to identify serving cells for the UEs, or initiate a change to the serving cells for one or more of the UEs.

Example Carrier Aggregation (CA) configuration during Dual Active Protocol Stack (DAPs) Handover (HO)

One of the goals of mobility enhancement is to achieve little to no interruption time during handover of a User Equipment (UE) between cells. In some cases, interruptions may be reduced by maintaining the source link during target link establishment using a make-before-break (MBB) Handover (HO) technique. During an MBB HO, the UE may be expected to maintain connectivity with the source and target base stations (e.g., the gNB). Such simultaneous connections with both the source and target base stations may involve certain beams/panels at the UE for transmission and reception from the source and target cells. Thus, the UE may maintain two separate protocol stacks during this HO. Thus, MBB HO may also be referred to as Dual Activity Protocol Stack (DAPs) HO. In some cases, the source cell may be in CA mode and the target cell may also need to be configured in CA mode before sending the DAPs HO command to the UE. In general, certain aspects of the present disclosure relate to techniques for CA configuration during a DAPs HO.

Fig. 7 is a call flow for MBB HO in accordance with certain aspects of the present disclosure. As shown, at event trigger, UE 702 may send measurement reports to source gNB Distributed Units (DUs) 704 and to a gNB Central Unit (CU)708 at step 1. Based on the measurement reports, the CU 708 may make MBB HO decisions. At step 2, a UE context setup request/response procedure with the target gNB-DU 706 is performed, as shown. At step 3, a Radio Resource Control (RRC) reconfiguration message may be sent to the source gNB-DU704 and the UE 702. The RRC reconfiguration message may configure the MBB HO such that the UE maintains a connection with the target and source gNB-DUs during the HO period. The RRC reconfiguration message may also configure the type of connection (e.g., single carrier, CA, or dormant CA) to be maintained with the target and source gNB-DUs during the HO period, as described in more detail herein. The type of connection to be maintained may be determined by the gNB-CU during the MBB HO decision.

At step 4a, data transmission and reception may continue with the source gNB-DU704 using the user plane functional unit 710, while a connection is established to the target gNB at step 4b (e.g., synchronization and Radio Access Channel (RACH) signaling are performed). Once the RRC connection reconfiguration is complete, the UE sends an RRC connection reconfiguration complete message to the target gNB-DU 706 and the gNB-CU 708 at step 5. The gsb-CU then makes a source gsb-DU connection release decision and, at step 6, performs a UE context modification request/response with the source gsb-DU 704. At step 7, an RRC reconfiguration message is sent to the target gNB-DU 706 and the UE, indicating to the UE to release the connection from the source gNB DU 704. The UE then releases the connection from the source gNB-DU704 and sends an RRC reconfiguration complete message to the target gNB-DU 706 and the gNB-CU 708, in response to which a UE context release from the source gNB-DU704 is performed at step 9.

As shown, during the HO period 720 (or at least a portion thereof), the UE maintains a connection with both the source and target gNB-DUs, thereby reducing any service interruption experienced by the user during the HO. In other words, the UE remains simultaneously connected with the source and target gNB-DUs during at least a portion of the HO period 720. For example, Downlink (DL) and Uplink (UL) signaling between the UE and the source gNB-DU704 and RACH signaling with the target gNB-DU 706 may be supported simultaneously. Further, the UE may support both DL and UL signaling with source gNB-DU704 and DL and UL signaling with target gNB-DU 706.

As described herein, CA can be implemented with target and source gNB-DUs. However, for some UEs, it may be difficult (or impossible) to support CA with both the target and source gNB-DUs. Certain aspects of the present disclosure relate to techniques for processing MBB HO with CA.

Fig. 8 illustrates a flowchart of example operations 800 for wireless communication, in accordance with certain aspects of the present disclosure. Operations 800 may be performed, for example, by a UE (e.g., such as UE 120 in wireless communication network 100).

Operations 800 may be implemented as software components executing and running on one or more processors (e.g., processor 480 of fig. 4). Further, the transmission and reception of signals by the UE in operation 800 may be implemented, for example, by one or more antennas (e.g., antenna 452 of fig. 4). In certain aspects, the transmission and/or reception of signals by the UE may be accomplished via a bus interface by one or more processors (e.g., processor 480) that obtains and/or outputs the signals.

The operations 800 may begin at block 802 by: the UE receives a message (e.g., an RRC reconfiguration message at step 3 in fig. 7) for DAPs HO from a source network entity (e.g., source gNB-DU704) to a target network entity (e.g., target gNB-DU 706), wherein the CA with the source network entity is configured prior to receiving the message for HO. At block 804, the UE may deactivate CA to activate a single carrier mode with the source network entity in response to receiving the message for HO, and at block 806, perform HO from the source network entity to the target network entity during a HO period (e.g., HO period 720). In certain aspects, a single carrier mode is maintained with a source network entity during at least a portion of a HO period, and wherein a connection is maintained with a target network entity during at least a portion of the HO period. In some cases, the message for HO may include an indication to deactivate CA mode with the source network entity, as described herein.

Fig. 9 illustrates example operations 900 for wireless communication in accordance with certain aspects of the present disclosure. Operation 900 may be performed, for example, by a BS (e.g., such as BS 110 in wireless communication network 100 or a gNB-CU in fig. 7).

Operations 900 may be implemented as software components executing and running on one or more processors (e.g., processor 440 of fig. 4). Further, the transmission and reception of signals by the BS in operation 1100 may be implemented, for example, by one or more antennas (e.g., antenna 434 of fig. 4). In certain aspects, the transmission and/or reception of signals by the BS may be accomplished via a bus interface for one or more processors (e.g., processor 440) to obtain and/or output signals.

The operations 900 may begin at 902 by: the BS generates a message for a dual-DAPs HO of the UE from a source network entity to a target network entity, wherein the CA is configured for communication between the UE and the source network entity prior to sending the message for the HO. In certain aspects, the message indicates to the UE to activate a single carrier mode with the source network entity during the HO period while maintaining a connection with the target network entity during at least the portion of the HO period. At 904, the BS sends a message for HO to the UE.

Fig. 10 is a timing diagram illustrating a connection pattern of a source cell (e.g., source network entity) and a target cell (e.g., target network entity) during an MBB HO in accordance with certain aspects of the present disclosure. During time period 1002, the UE may be connected with both the source cell and the target cell. As shown, CA mode may be deactivated completely on the source cell. The UE may configure a CA mode with the target cell after the UE connects to the target cell, or may configure a single carrier (e.g., single CC) mode with the target cell after the connection. In certain aspects, the source cell may send a CA reconfiguration message to the UE along with a DAPs HO command (e.g., an RRC reconfiguration message at step 3 of fig. 7) to deactivate CA. As shown, during the HO period 720 (or at least a portion thereof), a single carrier mode may be activated for the target cell.

Fig. 11 illustrates a flowchart of example operations 1100 for wireless communication, in accordance with certain aspects of the present disclosure. Operations 1100 may be performed, for example, by a UE (e.g., such as UE 120 in wireless communication network 100).

Operations 1100 may be implemented as software components executing and running on one or more processors (e.g., processor 480 of fig. 4). Further, the transmission and reception of signals by the UE in operation 1000 may be implemented, for example, by one or more antennas (e.g., antenna 452 of fig. 4). In certain aspects, the transmission and/or reception of signals by the UE may be accomplished via a bus interface by one or more processors (e.g., processor 480) that obtains and/or outputs the signals.

The operations 1100 may begin at block 1102 by: the UE receives a message for a DAPs HO from a source network entity to a target network entity, wherein Carrier Aggregation (CA) is configured for communication with the source network entity prior to receiving the message for the HO. At block 1104, the UE activates a dormant CA mode with the source network entity in response to receiving the message for HO, and at block 1106, performs HO from the source network entity to the target network entity during a HO period, wherein the dormant CA mode is maintained with the source network entity during at least a portion of the HO period, and wherein a connection is maintained with the target network entity during at least the portion of the HO period.

Fig. 12 illustrates example operations 1200 for wireless communication, in accordance with certain aspects of the present disclosure. Operations 1200 may be performed, for example, by a BS (e.g., such as BS 110 in wireless communication network 100 or a gNB-CU in fig. 7).

Operations 1200 may be implemented as software components executing and running on one or more processors (e.g., processor 440 of fig. 4). Further, the transmission and reception of signals by the BS in operation 1200 may be implemented, for example, by one or more antennas (e.g., antenna 434 of fig. 4). In certain aspects, the transmission and/or reception of signals by the BS may be accomplished via a bus interface for one or more processors (e.g., processor 440) to obtain and/or output signals.

The operations 1200 may begin at 1202 by: the BS generates a message for a DAPs HO of a User Equipment (UE) from a source network entity to a target network entity, wherein Carrier Aggregation (CA) is configured for communication between the UE and the source network entity prior to sending the message for the HO, wherein the message indicates to the UE to activate a dormant CA mode with the source network entity during at least a portion of the HO period while maintaining a connection with the target network entity during at least a portion of the HO period. At block 1204, the BS sends the message to the UE.

Fig. 13 is a timing diagram illustrating a connection pattern of a source cell (e.g., source network entity) and a target cell (e.g., target network entity) during an MBB HO in accordance with certain aspects of the present disclosure. As shown, the connection with the source cell may be in a dormant CA mode. In other words, a secondary cell (Scell) (e.g., a secondary component carrier) of the source cell may be dormant. In the dormant CA mode, the UE may not monitor control signaling (e.g., Physical Downlink Control Channel (PDCCH)) on the Scell during DAPs HO, even though the UE is in CA. Instead, the UE may monitor only the PDCCH on the primary cell. By activating the dormant CA mode (as opposed to deactivating CA), the CA activation/deactivation latency can be reduced without increasing the burden on the UE to monitor the PDCCH on the Scell. For example, in the dormant CA mode, scheduling of transmissions on the Scell may be performed via the primary cell using cross-carrier scheduling. The CA having the sleep mode may move to the target cell after the source cell is released, or the normal CA mode may be separately configured on the target cell. In other words, after the connection with the source cell is released (e.g., after step 7 in fig. 7), the UE may configure a CA mode with dormancy with the target cell, or normal CA for which the PDCCH is monitored on both the primary and secondary cells. In certain aspects, the source and target cells may be configured with CA during at least a portion of the HO period, allowing the UE to maintain CA with both the target and source cells without monitoring the secondary cells, thereby reducing the burden on the UE.

Fig. 14 illustrates a flowchart of example operations 1400 for wireless communication, in accordance with certain aspects of the present disclosure. Operation 1400 may be performed, for example, by a UE (e.g., such as UE 120 in wireless communication network 100).

Operation 1400 may be implemented as a software component that executes and runs on one or more processors (e.g., processor 480 of fig. 4). Moreover, the transmission and reception of signals by the UE in operation 1400 may be implemented, for example, by one or more antennas (e.g., antenna 452 of fig. 4). In certain aspects, the transmission and/or reception of signals by the UE may be accomplished via a bus interface by one or more processors (e.g., processor 480) that obtains and/or outputs the signals.

Operation 1400 may begin at block 1402 by: the UE receives a message for DAPs HO from a source network entity to a target network entity, wherein Carrier Aggregation (CA) is configured for communication with the source network entity prior to receiving the message. At block 1404, the UE performs a HO from the source network entity to the target network entity during a HO period, wherein a CA mode with the source network entity is maintained during at least a portion of the HO period, and wherein a connection with the target network entity is maintained during at least a portion of the HO period.

Fig. 15 illustrates example operations 1500 for wireless communication in accordance with certain aspects of the present disclosure. Operation 1500 may be performed, for example, by a BS (e.g., such as BS 110 in wireless communication network 100 or a gNB-CU in fig. 7).

Operations 1500 may be implemented as software components executing and running on one or more processors (e.g., processor 440 of fig. 4). Further, the transmission and reception of signals by the BS in operation 1500 may be implemented, for example, by one or more antennas (e.g., antenna 434 of fig. 4). In certain aspects, the transmission and/or reception of signals by the BS may be accomplished via a bus interface for one or more processors (e.g., processor 440) to obtain and/or output signals.

The operations 1500 may begin at 1502 by: a message is generated for DAPs HO of the UE from the source network entity to the target network entity. The CA mode may be configured for communication between the UE and the source network entity prior to sending the message for HO. The message may instruct the UE to maintain the CA mode with the source network entity during at least a portion of the HO period while maintaining the connection with the target network entity during at least the portion of the HO period. At block 1504, the BS transmits a message for HO to the UE.

Fig. 16 is a timing diagram illustrating connection patterns of a source cell (e.g., source network entity) and a target cell (e.g., target network entity) during MBB HO in accordance with certain aspects of the present disclosure. As shown, the CA pattern on the source cell and the target cell may be preserved during DAPs HO. To support the CA mode on both the source and target cells during a DAPs HO, certain resources may be allocated at the UE between the source and target cells. A UE with current capabilities may reallocate resources on both cells by, for example, reducing the number of component carriers supporting CA on each cell. For example, although a maximum of 8 CCs are allowed on one cell, an 8 CC limit may be shared between two cells (e.g., 4 CCs on each cell). In some cases, an extended-capability UE is able to activate a maximum of 8 CCs per cell. As described herein, to reduce UE burden, dormant CA may be activated on both cells during a HO period.

Fig. 17 illustrates a communication device 1700 that may include various components (e.g., corresponding to elements plus functional components) configured to perform operations for the techniques disclosed herein, such as the operations illustrated in fig. 8, 11, 14. The communication device 1700 includes a processing system 1702 coupled to a transceiver 1708 (e.g., a transmitter and/or receiver). The transceiver 1708 is configured to transmit and receive signals, such as the various signals described herein, for the communication device 1700 via the antenna 1710. The processing system 1702 may be configured to perform processing functions for the communication device 1700, including processing signals received and/or to be transmitted by the communication device 1700.

The processing system 1702 includes a processor 1704 coupled to a computer-readable medium/memory 1712 via a bus 1706. In certain aspects, the computer-readable medium/memory 1712 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 1704, cause the processor 1704 to perform the operations shown in fig. 8, 11, 14, or other operations for performing the various techniques discussed herein for a DAPS HO. In certain aspects, the computer-readable medium/memory 1712 stores: code for receiving 1714; code for deactivating/activating 1716; and code 1718 for performing the HO. In certain aspects, the processor 1704 has circuitry configured to implement the code stored in the computer-readable medium/memory 1712. The processor 1704 includes: a circuit for receiving 1720; a circuit for deactivation/activation 1722; and circuitry 1724 for performing HO.

Fig. 18 shows a communication device 1800 that may include various components (e.g., corresponding to elements plus functional components) configured to perform operations for the techniques disclosed herein, such as the operations shown in fig. 9, 12, 15. The communication device 1800 includes a processing system 1802 coupled to a transceiver 1808 (e.g., a transmitter and/or receiver). The transceiver 1808 is configured to transmit and receive signals for the communication device 1800, such as the various signals described herein, via the antenna 1810. The processing system 1802 can be configured to perform processing functions for the communication device 1800, including processing signals received by and/or to be transmitted by the communication device 1800.

The processing system 1802 includes a processor 1804 coupled to a computer-readable medium/memory 1812 via a bus 1806. In certain aspects, the computer-readable medium/memory 1812 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 1804, cause the processor 1804 to perform the operations shown in fig. 9, 12, 15, or other operations for performing the various techniques discussed herein for a DAPS HO. In certain aspects, the computer-readable medium/memory 1812 stores: code for generating 1814; and code for transmitting 1816. In certain aspects, the processor 1804 has circuitry configured to implement code stored in the computer-readable medium/memory 1812. The processor 1804 includes: a circuit for generating 1818; and a circuit for transmitting 1820.

Illustrative aspects

Aspect 1, a method for wireless communication, comprising: receiving a message for a Dual Activity Protocol Stack (DAPs) Handover (HO) from a source network entity to a target network entity, wherein Carrier Aggregation (CA) with the source network entity is configured prior to receiving the message for the HO; deactivating the CA in response to receiving the message for HO to activate a single carrier mode with the source network entity; and performing the HO from the source network entity to the target network entity during a HO period, wherein the single carrier mode is maintained with the source network entity during at least a portion of the HO period, and wherein a connection is maintained with the target network entity during the at least a portion of the HO period.

Aspect 2 the method of aspect 1, wherein the message for HO includes an indication to deactivate the CA mode with the source network entity.

Aspect 3 the method of any of aspects 1-2, wherein performing the HO comprises: receiving a configuration message indicating a release of a connection with the source network entity, the HO period including a period between the receiving the message for the HO and the receiving the configuration message.

Aspect 4 the method of any of aspects 1-3, further comprising: activating CA with the target network entity after the HO period.

Aspect 5 the method of any of aspects 1-4, wherein a single carrier mode with the target network entity is configured during the HO period.

Aspect 6 the method of any one of aspects 1-5, wherein a CA with the target network entity is configured during the HO period.

Aspect 7 is a method for wireless communication, comprising: receiving a message for a Dual Activity Protocol Stack (DAPs) Handover (HO) from a source network entity to a target network entity, wherein Carrier Aggregation (CA) is configured for communication with the source network entity prior to receiving the message; and performing the HO from the source network entity to the target network entity during a HO period, wherein the CA mode with the source network entity is maintained during at least a portion of the HO period, and wherein a connection with the target network entity is maintained during the at least a portion of the HO period.

Aspect 8 the method of aspect 7, wherein the CA pattern with the source network entity is configured with a smaller number of component carriers during the HO period than the CA pattern with the source network entity configured prior to the HO period.

Aspect 9 the method of any one of aspects 7-8, wherein a CA mode with the target network entity is configured during the HO period.

Aspect 10 the method of aspect 9, wherein the CA mode with the target network entity is configured with a smaller number of CCs during the HO period than a CA mode with the target network entity activated after the HO period.

Aspect 11, the method of any of aspects 7-10, wherein performing the HO comprises: receiving a configuration message indicating a release of a connection with the source network entity, the HO period including a period between the receiving the message for the HO and the receiving the configuration message.

Aspect 12, a method for wireless communication, comprising: generating a message for a Dual Activity Protocol Stack (DAPs) Handover (HO) of a User Equipment (UE) from a source network entity to a target network entity, wherein Carrier Aggregation (CA) is configured for communication between the UE and the source network entity prior to sending the message for the HO, and wherein the message indicates to the UE to activate a single carrier mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and sending the message for the HO to the UE.

Aspect 13, the method of aspect 12, further comprising: transmitting a configuration message to the UE indicating a release of a connection with the source network entity, the HO period including a period between the transmitting the message for HO and the transmitting the configuration message.

Aspect 14 the method of any of aspects 12-13, wherein the message for HO includes an indication that a single carrier mode with the target network entity is configured during the HO period.

Aspect 15 the method of any of aspects 12-14, wherein the message for HO includes an indication that CA with the target network entity is configured during the HO period.

Aspect 16, a method for wireless communication, comprising: generating a message for a Dual Activity Protocol Stack (DAPs) Handover (HO) of a User Equipment (UE) from a source network entity to a target network entity, wherein a Carrier Aggregation (CA) mode is configured for communication between the UE and the source network entity prior to sending the message for the HO, and wherein the message instructs the UE to maintain the CA mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and sending the message for HO to the UE.

Aspect 17 the method of aspect 16, wherein the message indicates that the UE remains with the CA mode of the source network entity with a lower number of component carriers during the HO period than the CA mode configured before the HO period.

Aspect 18 the method of any of aspects 16-17, wherein the message indicates that the UE configures a CA mode with the target network entity during the HO period.

Aspect 19 the method of aspect 18, wherein the CA mode with the target network entity is configured with a smaller number of CCs during the HO period than a CA mode with the target network entity activated after the HO period.

Aspect 20, the method of any one of aspects 16-19, further comprising: transmitting a configuration message to the UE indicating a release of a connection with the source network entity, the HO period including a period between the transmitting the message for HO and the transmitting the configuration message.

Aspect 21, a method for wireless communication, comprising: receiving a message for a Dual Activity Protocol Stack (DAPs) Handover (HO) from a source network entity to a target network entity, wherein Carrier Aggregation (CA) is configured for communication with the source network entity prior to receiving the message for the HO; activating a dormant CA mode with the source network entity in response to the receiving the message for HO; and performing the HO from the source network entity to the target network entity during a HO period, wherein the dormant CA mode is maintained with the source network entity during at least a portion of the HO period, and wherein a connection is maintained with the target network entity during the at least a portion of the HO period.

Aspect 22 the method of aspect 21, wherein control information on one or more secondary Component Carriers (CCs) is not monitored during the dormant CA mode.

Aspect 23 the method of any of aspects 21-22, wherein the message for HO includes an indication to activate the dormant CA mode with the source network entity.

Aspect 24 the method of any of aspects 21-23, wherein a single carrier mode of operation is maintained with the target network entity during the HO period.

Aspect 25 the method of aspect 24, wherein performing the HO comprises: receiving a configuration message indicating a release of a connection with the source network entity, the HO period including a period between the receiving the message for HO and the receiving the configuration message.

Aspect 26, the method of any of aspects 21-25, further comprising: activating CA with the target network entity after the HO period.

Aspect 27, the method of any one of aspects 21-26, further comprising: activating a dormant CA mode with the target network entity after the HO period.

Aspect 28 the method of any of aspects 21-27, wherein a dormant CA mode with the target network entity is configured during the HO period.

Aspect 29, a method for wireless communication, comprising: generating a message for a Dual Activity Protocol Stack (DAPs) Handover (HO) of a User Equipment (UE) from a source network entity to a target network entity, wherein Carrier Aggregation (CA) is configured for communication between the UE and the source network entity prior to sending the message for the HO, wherein the message indicates to the UE to activate a dormant CA mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and sending the message to the UE.

Aspect 30 the method of aspect 29, wherein the UE does not monitor control information on one or more secondary Component Carriers (CCs) during the dormant CA mode.

Aspect 31 the method of any of aspects 29-30, wherein the message for the HO includes an indication that a single carrier mode of operation with the target network entity is configured during the HO period.

Aspect 32, the method of any of aspects 29-31, further comprising: transmitting a configuration message to the UE indicating a release of a connection with the source network entity, the HO period including a period between the transmitting the message for HO and the transmitting the configuration message.

Aspect 33 the method of any of aspects 29-32, wherein the message for HO includes an indication for the UE to activate a dormant CA mode with the target network entity after the HO period.

Aspect 34 the method of any of aspects 29-33, wherein the message for HO includes an indication for the UE to activate a dormant CA mode with the target network entity during the HO period.

The methods disclosed herein comprise one or more steps or actions for achieving these methods. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including a single member. For example, "at least one of a, b, or c" is intended to encompass a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination of the same elements in multiple (e.g., a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b-b, b-b-c, c-c, and c-c-c, or any other ordering of a, b, and c).

As used herein, the term "determining" includes a wide variety of actions. For example, "determining" can include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining and the like. Further, "determining" can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and so forth. Further, "determining" may include resolving, selecting, establishing, and the like.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more. The term "some" means one or more unless explicitly stated otherwise. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed according to the provisions of clause 6 of united states patent law 112 unless the element is explicitly recited using the phrase "unit for … …," or in the case of a method claim, the element is recited using the phrase "step for … ….

The various operations of the methods described above may be performed by any suitable means capable of performing the corresponding functions. These units may include various hardware and/or software components and/or modules, including but not limited to: a circuit, an Application Specific Integrated Circuit (ASIC), or a processor. Generally, where there are operations shown in the figures, those operations may have corresponding counterpart functional unit components with similar numbering.

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable Logic Device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

If implemented in hardware, an example hardware configuration may include a processing system in the wireless node. The processing system may be implemented using a bus architecture. The bus may include any number of interconnecting buses and bridges depending on the specific application of the processing system and the overall design constraints. The bus may link together various circuits including the processor, the machine-readable medium, and the bus interface. The bus interface may also be used, among other things, to connect a network adapter to the processing system via the bus. Network adapters may be used to implement signal processing functions at the physical layer. In the case of a user terminal 120 (see fig. 1), a user interface (e.g., keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further. The processor may be implemented using one or more general and/or special purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits that can execute software. Those skilled in the art will recognize how best to implement the described functionality for a processing system depending on the particular application and the overall design constraints imposed on the overall system.

If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Software shall be construed broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. The processor may be responsible for managing the bus and general processing, including the execution of software modules stored on the machine-readable storage medium. A computer readable storage medium may be coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. By way of example, the machine-readable medium may include a transmission line, a carrier waveform modulated by data, and/or a computer-readable storage medium separate from the wireless node having instructions stored thereon, all of which may be accessed by the processor through a bus interface. Alternatively or in addition, the machine-readable medium or any portion thereof may be integrated into a processor, for example, as may be the case with a cache and/or a general register file. Examples of a machine-readable storage medium may include, by way of example, RAM (random access memory), flash memory, ROM (read only memory), PROM (programmable read only memory), EPROM (erasable programmable read only memory), EEPROM (electrically erasable programmable read only memory), registers, a magnetic disk, an optical disk, a hard drive, or any other suitable storage medium, or any combination thereof. The machine-readable medium may be embodied in a computer program product.

A software module may comprise a single instruction, or many instructions, and may be distributed over several different code segments, among different programs, and across multiple storage media. The computer readable medium may include a plurality of software modules. The software modules include instructions that, when executed by an apparatus, such as a processor, cause a processing system to perform various functions. The software modules may include a sending module and a receiving module. Each software module may reside in a single memory device or be distributed across multiple memory devices. For example, when a triggering event occurs, a software module may be loaded from a hard drive into RAM. During execution of the software module, the processor may load some of the instructions into the cache to increase access speed. One or more cache lines may then be loaded into the general register file for execution by the processor. It will be understood that when reference is made below to the functionality of a software module, such functionality is achieved by the processor upon execution of instructions from the software module.

Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as Infrared (IR), radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk and

optical disks, where disks usually reproduce data magnetically, while optical disks reproduce data optically with lasers. Thus, in some aspects, computer-readable media may comprise non-transitory computer-readable media (e.g., tangible media). Further, for other aspects, a computer-readable mediumMay include a transitory computer readable medium (e.g., a signal). Combinations of the above should also be included within the scope of computer-readable media.

Accordingly, certain aspects may comprise a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium having instructions stored (and/or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein. Such as instructions for performing the operations described herein.

Further, it should be appreciated that modules and/or other suitable means for performing the methods and techniques described herein can be downloaded and/or otherwise obtained by a user terminal and/or base station (if applicable). For example, such a device may be coupled to a server to facilitate communicating means for performing the methods described herein. Alternatively, various methods described herein can be provided via a storage unit (e.g., RAM, ROM, a physical storage medium such as a Compact Disc (CD) or floppy disk, etc.), such that a user terminal and/or base station can obtain the various methods upon coupling or providing the storage unit to the device. Further, any other suitable technique for providing the methods and techniques described herein to a device may be used.

It is to be understood that the claims are not limited to the precise configuration and components shown above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

Claims (20)

1. A method for wireless communication, comprising:

receiving a message for a Dual Activity Protocol Stack (DAPs) Handover (HO) from a source network entity to a target network entity, wherein Carrier Aggregation (CA) with the source network entity is configured prior to receiving the message for the HO;

deactivating the CA in response to receiving the message for HO to activate a single carrier mode with the source network entity; and

performing the HO from the source network entity to the target network entity during a HO period, wherein the single carrier mode is maintained with the source network entity during at least a portion of the HO period, and wherein a connection is maintained with the target network entity during the at least a portion of the HO period.

2. The method of claim 1, wherein the message for HO comprises an indication to deactivate the CA mode with the source network entity.

3. The method of claim 1, wherein performing the HO comprises: receiving a configuration message indicating a release of a connection with the source network entity, the HO period including a period between the receiving the message for the HO and the receiving the configuration message.

4. The method of claim 1, further comprising: activating CA with the target network entity after the HO period.

5. The method of claim 1, wherein a single carrier mode with the target network entity is configured during the HO period.

6. The method of claim 1, wherein a CA with the target network entity is configured during the HO period.

7. A method for wireless communication, comprising:

receiving a message for a Dual Activity Protocol Stack (DAPs) Handover (HO) from a source network entity to a target network entity, wherein Carrier Aggregation (CA) is configured for communication with the source network entity prior to receiving the message; and

performing the HO from the source network entity to the target network entity during a HO period, wherein the CA mode with the source network entity is maintained during at least a portion of the HO period, and wherein a connection with the target network entity is maintained during the at least a portion of the HO period.

8. The method of claim 7, wherein the CA mode with the source network entity is configured with a smaller number of component carriers during the HO period than the CA mode with the source network entity configured prior to the HO period.

9. The method of claim 7, wherein a CA mode with the target network entity is configured during the HO period.

10. The method of claim 9, wherein the CA mode with the target network entity is configured with a smaller number of CCs during the HO period than a CA mode with the target network entity activated after the HO period.

11. The method of claim 7, wherein performing the HO comprises: receiving a configuration message indicating a release of a connection with the source network entity, the HO period including a period between the receiving the message for the HO and the receiving the configuration message.

12. A method for wireless communication, comprising:

generating a message for a Dual Activity Protocol Stack (DAPs) Handover (HO) of a User Equipment (UE) from a source network entity to a target network entity, wherein Carrier Aggregation (CA) is configured for communication between the UE and the source network entity prior to sending the message for the HO, and wherein the message indicates to the UE to activate a single carrier mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and

sending the message for the HO to the UE.

13. The method of claim 12, further comprising: transmitting a configuration message to the UE indicating a release of a connection with the source network entity, the HO period including a period between the transmitting the message for HO and the transmitting the configuration message.

14. The method of claim 12, wherein the message for HO comprises an indication that a single carrier mode with the target network entity is configured during the HO period.

15. The method of claim 12, wherein the message for HO comprises an indication to configure CA with the target network entity during the HO period.

16. A method for wireless communication, comprising:

generating a message for a Dual Activity Protocol Stack (DAPs) Handover (HO) of a User Equipment (UE) from a source network entity to a target network entity, wherein a Carrier Aggregation (CA) mode is configured for communication between the UE and the source network entity prior to sending the message for the HO, and wherein the message instructs the UE to maintain the CA mode with the source network entity during at least a portion of a HO period while maintaining a connection with the target network entity during the at least a portion of the HO period; and

sending the message for HO to the UE.

17. The method of claim 16, wherein the message indicates that the UE remains with the CA mode of the source network entity with a fewer number of component carriers during the HO period than the CA mode configured prior to the HO period.

18. The method of claim 16, wherein the message indicates that the UE configures a CA mode with the target network entity during the HO period.

19. The method of claim 18, wherein the CA mode with the target network entity is configured with a smaller number of CCs during the HO period than a CA mode with the target network entity activated after the HO period.

20. The method of claim 16, further comprising: transmitting a configuration message to the UE indicating a release of a connection with the source network entity, the HO period including a period between the transmitting the message for HO and the transmitting the configuration message.

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